Mold for concrete bombs



NOV. 6, 1945. R PETERSEN 2,388,569

MOLD FOR CONCRETE BOMBS.

Filed Dec. 26, 1944 3 Sheets-Sheet l 9 R. P. PETERSEN 2,388,569

MOLD FOR CONCRETE BOMBS Filed Dec. 26, 1944 5 Sheets-Sheet 2 Nov.6, 1945. v R R P TE N 2,388,569

MOLD FOR CONCRETE BOMBS' Filed Dec. 25, 194 3 SheetS-Sheet IS Patented Nov. 6, 1945 UNITED STATES PATENT OFFICE 2,388,569 MOLD FOR. CONCRETE BOMB-S Robert P. Petersen, Philadelphia, Pa. Application December 26, 1944, Serial No. 569,803

'1 Claims.

This invention relates to the manufacture of concrete practice bombs and more particularly to forms or molds for making such bombs.

Actual bombing practice is desirable in developing the bombing proficiency of military aviation personnel, and large quantities of practice bombs are expended in such training. These practice bombs are required to have the'same size, shape, weight and flight characteristics as actual bombs if the practice results are to represent. the results of actual bombing with any degree of accuracy. As heretofore made, such practice bombs have usually consisted of metal casings of the desired size and shape and adapted to. be filled with sand or the like to make up the proper weight. Both the cost of materials and the cost. of manufacture have been high, and

moreover the variation in weight. of the sand: according to. moisture conditions has caused variations in results which have gone'far to nullify the desired benefit of the practice. Concrete bombs, on the other hand, can be madequickly andcheaply of nomcritical materials, can be molded to the exact size and shape desired, do not need to be filled before use, are of uniform and: non-varying Weight, andprovide entirely satisfactory results.

The present invention is concerned with the moldin of such concrete practice bombs having the characteristic: shapeof a substantially cylindrisal bo y wi h a rounded nose and a tapered conical base In, addition. provision must bemade for accurately located bolts set intheconcrete base but protruding for attachment of the usual metal fin, for. axially aligned lugs on the. side of the bomb for susp it in the bomb rack, which lugs must line up accurately with one of the vanes of the fin, and for a charging recess in the base in which a container of smoke-producing material or the like can be inserted.

The invention provides a. novel mold. or form for these purposes which is light and inexpensive, simple to assemble, or knockdown, and. easy to use, while at the same. time providing accurate location and alignment of the suspension lugs, firm-attaching bolts, and charging recess... moldcomprises three ,main sections, namely, a plural-part substantially cylindrical shell having a pouring opening at its nose and axially aligned openings for the suspension lugs, a nose piece to be inserted in said nose opening after the bomb isimured and having a rounded inner surface to shaperthe nose of the bomb, and a base assembly supporting the, shell and: forming the tapered of. the bmnbwith its chargingrecess and fin-attach-ing bolts. I'hea-ssembled shell is locked to the base assembly with the lug openings and bolts properly aligned while the bomb is being poured but is thereafter stripped off leawng the formed bomb supported by the base assembly: for curing.

One embodiment of the invention has been il lustrated in the accompanying drawings, but it isto be expressly understood that said drawings are for purposes of illustration only and are not to be construed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings: V

Fig. 1 is a side View of a complete assembled mold embodying the. invention;

Fig. 2 is: asection. on the line 2-.2. of Fig. 1;

Fig. 3' is a top plan view of Fig. I;

Fig. 4. is. abottom plan view of Fig- 1;

.Fig'. 5- isa section. on the line 51-5; of Fig.2;

6; is a. section through the. base assembly on the line.- 6.-6 of Fig. 4.; i

Fig; '2 is a section of the base. assembly on the line 1-1 of Fig. 4;

Figs. 8 and 9 are. detail views. illustrating locks ing, means. for attachingthe shell to the base assembly;

Figs. 10-and 11 are detailv views illustratingqthe cooperating locking means. on the base assembly;

Eigs. 12 and, 13 illustrate the; assembly of. these locking means;

Fig, 14 is adetail of part of the shell;

, Figs. 15,, 16,, 17; and. 1.8. illustrate details. of; the base assembly.

The shell in the. form shown consists oii two half-cylindrical parts I the meeting edges. of which are provided with angles haying circumferential flanges 2. welded to the, shell parts and radial flanges 3 which engageone anctherand are locked together in any suitable manner. In; the form shown, studs 4 are welded. to one or the flanges 3 and extend through openings the adjacent, flange 3, the protruding ends of these studs having openings through which wedges 5 are driven to. lock the flanges tightly together.

The shell parts I are rounded off as shown atfi to form the tapering nose of the projectile and terminate in a two-part ring I. providing. apouring opening at the nose, the ends of the radial flanges 3 being bent over and welded, to this. ring at 8. A nose piece or plug 9' is shaped, to fit tightly in the ring I and to closev the pouring opening, said nose piece having a rounded; or curved inner surface- III- which completes the shaping ofv the nose of the projectile;

The shell parts are also provided with a plurality of axially aligned openings whereby the suspension lugs can be molded into the bomb. In the form shown, openings H are cut through the radial flanges 3 andv through the circumferential flanges 2 of the stiffening angles and the shell beneath, as shown in Figs. 1 and 2. Mating openings are provided in the two shell parts and when the shell is assembled, these openings merge (Fig. 14) and provide for the location of the suspension lugs along the axial line of the flanges 3.

The base assembly comprises an inverted conical cup I2 which forms the tapered base of the bomb, this cup being preferably mounted in a fabricated sheet metal assembly which supports the shell while the bomb is being poured and which supports the formed bomb during curing of the concrete as stated above. shown, this assembly comprises four supporting legs l3 generally triangular in shape and preferably formed from sheet metal flanged at I along their bottom edges to provide greater supporting area, said legs being arranged substantially radially with their inner edges flanged at |5 for attachment to the cup |2 as by spot welding. The outer edges of the legs may be stiflened by flanges I6.

A central opening inthe bottom of the cup |2 is adapted to receive and locate a core piece l8 (Fig. 7) which forms a charging recess in the tapered base of the bomb. A plurality of smaller openings l9, here shown as four in number, are formed in the bottomof the cup |2 around the central opening H to receiveand locate fin attaching bolts the heads of which are molded in the base of the bomb and the lower ends of which extend below the bottom of the cup 50 that they protrude from the base of the finished bomb. Beneath the bottom of the cup, the lower ends of the core piece"! and bolts 20 are vertically located and supported by suitable means such as a plate 2| forming part of the base assembly. Preferably this plate is notched at 22 (Fig. 17) to receive the inner edges of the legs I3, said legs extending inwardly beneath the plate and terminating at a ring 23 having anupper flange 24 on which the plate 2| is supported. These parts may be secured together in any suitable manner as by spot welding at appropriate points.

Preferably the lower ends of the core piece l8 and bolts 20 beneath the bottom of the cup are held in proper alignment while the bomb is being poured. For this purpose an alignment plate 25 (Figs. 15 and 16) is suspended from the bottom of the cup in any suitable manner, as by the upturned lugs 26 the ends of which extend through openings in the bottom of the cup |2 and are upset to secure the alignment plate in position. This plate is provided with a central opening 21 corresponding to the central opening H in the bottom of the cup, and with four surrounding openings 28 corresponding to the openings IS in the bottom of the cup. Thus the core piece and the bolts are firmly engaged at spaced of .the suspension lug openings H in a predeter- In' the form.

mined circumferential position with respect to the fin-attaching bolts 20. It will be understood that the relation of this predetermined position relative to the bolts 20 will depend upon the position which the vane of the fln will occupy with respect to the bolts 2|].

The details of suitable indexing and locking means are illustrated in Figs. 8-13. Secured to the bottom of the shell parts is a two-part ring 29 (Figs. 8 and 9) having a horizontal shell supporting portion 30 and a downturned peripheral flange 3|. Secured to the upper edge of the cup v I2 is a cooperating supporting ring (Figs. 10 and '11) having a horizontal flange 32 supporting the horizontal flange 30 of the shell ring, an inner peripheral flange 33 attached to the rim of the cup I2 as by spot welding, and an outer vdownturned peripheral flange 34 over which that the ends of the flanges 3| can slide under the horizontal flange 32 and inside the lugs 35 of the base ring (Figs. 12 and 13). The ends of the flanges 3| can be cut off to less than a half circumference if desired, as shown in Figs. 8, 9 and 1 The engagement of the ends of the flanges 3| under the horizontal flange 32 locks the shell to the base assembly against vertical or axial displacement, and the location of the lugs 35 fixes the rotational position of the shell relative to the base assembly. The axial line of the suspension lug openings H is thus definitely fixed relative to the position of the bolts 20 and hence properly located relative to the'vane of the fin to be subsequently attached.

The use of the mold will be clear from the foregoing description and may be summarized as follows. The core I8 and bolts 20 are placed in the base assembly, and the two halves of the shell are pushed on the base assembly from opposite sides, engaging the locking and indexing means described above. The Wedges 5 are then inserted and driven tight,'the suspension lugs are inserted, and the mold is ready for pouring. If desired, suitable reinforcing meansmay be placed between the halves of the shell, and in such case the'suspension lugs may form part of or be attached to the reinforcement. The bomb is then poured and the nose piece inserted to finish the nose. Tamping, shaking or other suitable operations may be employed if desired. When .the concrete has set sufliciently to be self-supporting, the shell and nose piece are removed, leaving the bomb supported in, the base assembly while curing. V

It will be understood that the invention is not limited to the particular embodiment described above and illustrated in the drawings, as various changes. may be made in the form, details of construction andarrangement of the parts without departing from its spirit. Reference should therefore be had to ,the appended claims for a definition of the limits of theinvention.

What is claimedis: a Y

.1. A mold formaking concrete practice bombs comprising a plural-part substantially cylindrical shell hav ne'a pouring opening at the nose, means for locking the'parts of said shellin assembled relation, abase assembly supportingthe mold and having an inverted conical cup to form the tapered base of the bomb, and means for locking the assembled shell to the base assembly, said cup having a central opening in its bottom to locate a core piece forming a charging recess in the base of the bomb, said base assembly comprising a support for said core piece spaced a predetermined amount below the bottom of the cup to locate the lower end of said core piece.

2. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of said shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, and means for locking the assembled shell to the base assembly, said cup having a central opening in its bottom to locate a core piece forming a charging recess in the base of the bomb, said base assembly comprising means below the bottom of the cup surrounding and aligning said core piece and a support for said core piece below said aligning means and spaced a predetermined amount below the bottom of said cup to locate the lower end of said core piece.

3. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of said shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, and means for locking the assembled shell to the base assembly, the bottom of said cup having a plurality of openings to receive and locate fin-attaching bolts, said base assembly comprising supporting means for said bolts spaced a predetermined amount below the bottom of said cup to locate the lower ends of said bolts,

4. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of said shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, and means for locking the assembled shell to the base assembly, the bottom of said cup having a plurality of openings to receive and locate fin-attaching bolts, said base assembly comprising a plate below the bottom of the cup having corresponding openings to receive and align said bolts and supporting means for said bolts below said plate and spaced a predetermined amount from the bottom of said cup to locate the lower ends of said bolts,

5. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of the shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, the bottom of said cup having a central opening to locate a core piece forming. a charging recess in the base of the bottom and a plurality of openings around said central opening to receive and locate finattaching bolts, said base assembly comprising supporting means spaced a predetermined amount below the bottom of said cup for supporting and locating the lower ends of the core piece and bolts, and means for locking the assembled shell to the base assembl while the bomb is being poured.

6. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of the shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, the bottom of said cup having a central opening to locate a core piece forming a charging recess in the base of the bottom and a plurality of openings around said central opening to receive and locate fin-attaching bolts, said base assembly comprising a plate below the bottom of the cup having corresponding openings to receive and align said core piece and bolts and supporting means below said plate and spaced a predetermined amount below the bottom of said cup for supporting and locating the lower ends of said core piece and bolts, and means for locking the assembled shell to the base assembly while the bomb is being poured.

7. A mold for making concrete practice bombs comprising a plural-part substantially cylindrical shell having a pouring opening at the nose, means for locking the parts of the shell in assembled relation, a base assembly supporting the mold and having an inverted conical cup to form the tapered base of the bomb, the bottom of said cup having a central opening to locate a core piece forming a charging recess in the base of the bottom and a plurality of openings around said central opening to receive and locate finattaching bolts, said shell having a plurality of axially aligned openings to receive suspension lugs for the bomb, and means for locking the assembled shell to the base assembly comprising indexing means to locate the line of said lug openings in a predetermined circumferential position with respect to said bolts so that the lugs will be aligned with one of the vanes of the fin.

ROBERT P, PETERSEN. 

